Railway signaling system.



H. W. LEWIS. RAILWAY SIGNALING SYSTEM.

APPLIOATION FILED MAY 6, 1909. 991,072.,-

Patented May 2, 1911,

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tnvrrn sa W Wm HARRY W. LEWIS, OF BETHLEHEM, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH AND SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION 035 PENN- SYLVANIA.

To all whom it may concern.

Be it known that I, HARRY W. LEWIS, a citizen of the United States, residing at Bethlehem, in the county of Lehigh and State of Pennsylvania, have invented certain new and useful Improvements in Railway Signaling Systems, of which the following is a specification.

My invention relates to a railway signaling system, and particularly to the signaling system known in the art as the stafi system of signaling. There are two general types of such a signaling system known in the art, one the absolute and the other permissive. Such signaling systems are generally used on single track railways where the tratfic is in both directions.

In the absolute staff system generally two instruments or machines are employed at each end of the section of track to which the system is applied; and the removal of a staff from one of the instruments employed, locks both instruments'so that a second stafi can not be removed from either until the first staff has been inserted in either of the two instruments. The stafi so removed is given to the engine-driver or conductor of the train and constitutes his authority to proceed along the protected section of track. It will be seen at once that only a limited amount of traffic can be controlled within a given space of time by such a system. In the permissive stafi system in addition to the usual staiis employed for the two machines, there is also employed a permissive staff and a set of tablets. lVith the permissive system, more than one train can be passed in the same direction by a removal of a staff from one of the instruments, and using it to release a permissive stafi and one or more tablets, one of which tablets is given to each train. The last train carries the permissive stafi and all of the remaining tablets. Until this permissive stafi and all the tablets have been inserted in the other machine, no staff can be removed from either machine.

The permissive system enables a greater number of trains to be handled within a limited space of time than does the absolute system, but even the permissive system has a limited use, for it may happen that a number of trains may be run in the same direction (suificiently large to exhaust all the tablets) without any train being run Specification of Letters Patent.

Application filed May 6, 1909.

Patented May 2, I911.

Serial No. 494,483.

in the opposite direction and additional trains waiting to be sent in the first direction. Under these circumstances two courses are openone to send each train through by separate staiis, which consumes a great deal of time, or else a trip from one machine to the other and back again, to bring the permissive staff and tablets, which also consumes time. By my invention I make each staff not only absolute, but permissive as well. In other words, I may employ the machines and stati s of the absolute system and by changing the construction of stafls employed to embody my invention, make such absolute system a permissive system as well as permitting of its use as an absolute system. Thus the additional mechanism and circuits necessary to make an absolute system a permissive system are dispensed with. My invention permits of a greater number of trains being handled within a given space of time than by any of the absolute or permissive systems known or in use, while at the same time retaining all of the advantages of both.

I will describe a staii embodying my in vention and then point out the novel features thereof in claims:

Referring to the accompanying drawing, the figure shows a side elevation of one form of stafi enbodying my invention.

A staff of this type is particularly adapted for use in connection with a stafi? system such as is illustrated and described in Letters Patent No. 794,423 granted to T. H. Patenall on July 11, 1905, it being understood however that I do not limit myself to the form of staff instrument therein shown, or to the electrical circuits employed. 1 wish it particularly understood that a staii or stafis embodying my invention may be used in connection with any staff instrument and system.

My invention provides for making each staff in sections, the several sections being formed or provided with projections, recesses, etc, so arranged that the assembling of the sections to form the staff can be done in only one arrangement.

When the sections are assembled and held together, the system in which they are used may be made an absolute system, but when there are a number of trains to be passed through the sect-ion of track in the same direction, the staff is disjoined and a section or piece given to each train in the same manner as the tablets in the permissive staff system. After the trains have passed out of the protected section of track, the several pieces of the staff are assembled and fastened together and the staff inserted in the machine at the end of the protected section opposite to that from which it was removed.

It will be seen at once that no matter what the conditions are, one or a number of trains (according to the number of sections comprising each stafi) may be passed through without delay.

Referring now to the figure, the staff is shown as being composed of six sections U, V, WV, X, Y, and Z. The several sections are shown as being united by a rod U which extends through a central opening of each piece or section, and which rod has a transverse piece U fitting in a groove a in the end piece Z, and a screw thread which engages a screw thread in the other end section or piece U. The sections or pieces U, V, are so formed at their meeting faces as to permit of a relative turning movement when the end piece is being screwed onto the rod U. Of course other fastening means for joining the several sections together may be employed without departing from the spirit of my invention. The ad j acent faces of the several sections or pieces are provided with specially formed faces, the object of which is in assembling a disjoined staff to have only the proper sections or pieces for'each staff. The arrangement of the surfaces of the adjacent faces will be different for each staff and it will be seen at once that many such combinations may exist. The stafi' may be divided into sections in any desired manner and assembled and fastened together in any desired way, the idea of my invention being a staff for a stafi system of signaling which may be used singly to pass a train through a section of track or divided to pass a number of trains in the same direction throrwh a section of track.

Having thus described my invention, What I claim is: A

1. In combination with a staff instrument, a staff for use therewith comprising 5 in only one arrangement, and means for detachably holding the pieces together.

3. In combination with a staff instrument, a stafi for use therewith comprising 'a plurality of pieces, said pieces having matching projections and recesses in their faces, but having their pairs of adjacent faces unlike to permit of assembling in only one arrangement of the pieces, and means for detachably holding the pieces together.

4. In combination with a staff instrument, a staff for use therewith comprising a plurality of pieces, each having a face adapted to match with but one face of but one other piece, and means for detachably holding the pieces together.

In testimony whereof, I have signed my name to this specification in the-presenceof two subscribed witnesses.

HARRY W. LEWIS.

Witnesses:

G120. E. CnUsE, M. S. KIRKLAND.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). O. 

